基于查找表的功放线性预失真方法研究

在无线通信系统中,高功率放大器因其具有非线性特性,会导致频谱再生和邻道干扰等问题。为克服这一特征,采用一种基于查找表的自适应预失真方法。首先对查找表进行初始化,再采用自适应算法实时更新查找表内容,从而有效消除功放的非线性失真。仿真实验表明,该自适应预失方法可降低互调失真(IMD),能有效提高功放线性度,从而提高系统性能。

LUT method of predistortion compensate for linearization of HPA

In the wireless communication systems, the nonlinearity of high power amplifier (HPA) cause spectral spreading and adjacent channel interference. This paper proposes an adaptive predis-torter,which is composed of a look-up table ( LUT), that can compensate for the distortion by an HAP. Fist, initialize the LUT, Furthermore, an adaptive algorithm is proposed to compensate for the time-varying property of an HPA,as a result,the distortion can be eliminated greatly. Experimental results show that a 15 dB improvement in IMD is obtained, the efficiency of amplifier is improved effectively and the performance of system is increased.